If you look closer into the Michael Baddeley patreon, there are two levels, one where you don't have to subscribe and can download the bulk of the files for no charge, and then there is his pre-release stuff that is only available to Patreons.
This also contains some non-droid related content as well as tutorials ect.
You can purchase from some members parts they manufacture for R2D2 droids and this is endorsed by the club.
I don't think Michael is breaking the rules as such, and the Astromech club is aware of his files, if there was a problem, they would have acted on it by now.

I know that Disney/Lucasfilm do go through thingiverse, as I have seen them submit take down requests for some models, but it has always been for complete models where the maker requires you to make some kind of payment to get the files (even if not to the maker themselves).

This is why I don't really support sales on this site, as it gets complicated with all the club rules. That being said, if you have a component that can be used for general droid assembly, not specifically SW Droids, then I see no reason why you can't advertise it here - for example: panel hinges.

There is a current battle on thingiverse that a certain user is sharing a lot of professionally created files.
Yes fan art is very very grey in who owns what and what people can do. Basically if I see that a person has put work into something I would like, I don't mind paying him/her, this could be patreon or paypal.

The unfortunate thing is that people are getting angry and in this day and age things will go to far. It could even mean that thingiverse could go
forever if it blows out anymore. Yes thingiverse has a lot of silly stuff but this stuff is what people have spent their time learning and adapting from other peoples work. It needs to stay but the bad apples will spoil it if they keep posting this stuff.